Methods for generating animals with desirable traits

Abstract

Genetic tests, such as whole genome analysis (WGA), have been employed to identify genetically superior embryos. The disclosed methods extend in vitro culture time of embryos while awaiting results of genetic tests being performed on a portion of the same embryos. The disclosed methods also help expand the number of cells in each embryo before implantation in the recipient.

What is claimed is: 
     
       1. A method for producing a non-human mammalian progeny having a genetically desirable trait, the method comprising:
 (a) culturing a non-human mammalian embryo in vitro to establish a candidate cell line comprising from about 300 to about 800 cells; 
 (b) dividing the cells of the candidate cell line into two or more aliquots; 
 (c) subjecting a first aliquot from the two or more aliquots to a genetic analysis to test for the presence of one or more genes and/or one or more polymorphisms associated with the genetically desirable trait, wherein the presence in the first aliquot identifies the candidate cell line as having the genetically desirable trait; 
 (d) if the first aliquot does not comprise the genetically desirable trait, repeating steps (a)-(c) with a subsequent non-human mammalian embryo until the candidate cell line having the genetically desirable trait is identified; and 
 (e) producing, using cells from a second aliquot from the two or more aliquots from the candidate cell line identified as having the genetically desirable trait, the non-human mammalian progeny having the genetically desirable trait. 
 
     
     
       2. The method of  claim 1 , wherein the candidate cell line comprises from about 400 to about 800 cells at the end of step (a). 
     
     
       3. The method of  claim 2 , wherein the embryo comprises from about 100 to about 200 cells at the onset of the culturing step. 
     
     
       4. The method of  claim 1 , wherein the production of the progeny involves transferring a nucleus of a cell from the second aliquot into an enucleated oocyte. 
     
     
       5. The method of  claim 1 , comprising freezing the cells of at least one aliquot from the two or more aliquots that has not been subjected to the genetic analysis. 
     
     
       6. The method of  claim 5 , wherein the cells that are frozen are later thawed. 
     
     
       7. The method of  claim 1 , wherein the genetic analysis comprises one or more assays selected from the group consisting of: whole genome analysis (WGA); gene expression profiling using microarray; sequencing of a coding region of the one or more genes; sequencing of a non-coding region of the one or more genes; and whole genome sequencing. 
     
     
       8. The method of  claim 1 , wherein the two or more aliquots consist of between two and ten aliquots. 
     
     
       9. The method of  claim 1 , wherein the one or more polymorphisms are each individually selected from the group consisting of: single nucleotide polymorphisms, insertions, deletions, inversions, and mutations. 
     
     
       10. The method of  claim 1 , wherein the one or more polymorphisms include single nucleotide polymorphisms. 
     
     
       11. A method for producing a bovine progeny having a genetically desirable trait, the method comprising:
 (a) culturing a bovine embryo in vitro for 5 to 9 days; 
 (b) following the culturing of the embryo, transferring the cultured embryo into a recipient female; 
 (c) collecting the post-transfer embryo from the recipient female; 
 (d) culturing the cells from the post-transfer embryo in vitro to establish a candidate cell line; 
 (e) dividing the cells of the candidate cell line into two or more aliquots; 
 (f) subjecting a first aliquot from the two or more aliquots in step (e) to a genetic analysis to test for the presence of one or more genes and/or one or more polymorphisms associated with the genetically desirable trait, wherein the presence in the first aliquot identifies the candidate cell line as having the genetically desirable trait; 
 (g) if the first aliquot does not comprise the genetically desirable trait, repeating steps (a)-(f) with a subsequent bovine embryo until the candidate cell line having the genetically desirable trait is identified; and 
 (i) producing, using cells from a second aliquot from the two or more aliquots from the candidate cell line identified as having the genetically desirable trait, the bovine progeny having the genetically desirable trait. 
 
     
     
       12. The method of  claim 11 , wherein the collecting of the fetus occurs about 10 to 40 days post-transfer. 
     
     
       13. The method of  claim 11 , wherein the collecting of the fetus occurs about 10 to 30 days post-transfer. 
     
     
       14. The method of  claim 11 , wherein the collecting of the fetus occurs at about 14 to about 19 days post-transfer.